Both soil temperature and soil water condition are important factors that influencing soil respiration at different temporal scales. There is still intra and inter-seasonal variations in soil temperature and soil water content although they are seasonally correlated. In this study, a field experiment was carried out to explore effects of diurnal variations in soil temperature and soil water on soil respirations (R_S) in the alpine meadows in Balang Mountain in West Sichuan of China. The objectives of our study are to: 1) understand the seasonal pattern of day- and night-time R_S, in particular, nocturnal variations of R_S, 2) elucidate the partitioning pattern of day- and night-time R_S, and 3) compare Q₁₀ values of day- and night-time R_S. We examined both day- and night-time R_S by using LI-8100 Automated Soil CO₂ Flux System on monthly basis from April to November, 2011. The effects of soil temperature and soil water on R_S of alpine meadow were analyzed based on field measurements of diurnal soil respiration. The results indicated that R_S showed large seasonal variations in day- and night-time during the measurements period, with a two-peak curve in the day-time and parabola curve at the night-time. During the measurements period (April to November), the means of R_S in the day- and night-time are 1.83 μmol·m^-2·s^-1 and 1.61μmol·m^-2·s^-1, respectively. The means of daytime and nighttime R_S were significantly higher in growing seasons (Jun to September) than that in green up period (April to May) and withering period (October to November) which accounted largest contribution to annual soil respiration. The nocturnal soil respiration appeared to have similar tendency of variations among measurements, and it was relatively low at night-time, with the lowest between 06:30 and 07:00am. During the measurement period, Van't Hoff equation and Lloyd & Taylor function were the same to be used for describing the relationships between soil respiration and soil temperature. The two-factor equations (soil temperature and moisture content) were much better to describe responses of nocturnal soil respiration compared to the single-factor equations. Soil respiration rates in the day-time and night-time exhibited a significantly exponential correlation with soil temperature during green up period, growing season and weathering periods, while the linear positive relationships between soil respiration and soil water content were found for nocturnal respiration in green up period and for both day-time and nocturnal respirations in weathering period. Q₁₀ values were estimated to be 3.90 and 3.74 for the day-time and night-time respirations respectively, during the whole measurement period. Soil Q₁₀ values varied with season, but daytime soil respiration during the green up period was most sensitive to temperature, and the nocturnal soil respiration during the peak months of growing seasons was least sensitive to temperature. Our results demonstrated that soil temperature, soil water, and their interactive effects had distinct effects on soil respiration of either the day-time or night-time during the measurements period in the subalpine meadow. Therefore, more measurements of the soil nocturnal CO₂ efflux are essential to accurately estimate the seasonal and annual carbon fluxes based on instantaneous measurements of soil respiration. At the same time, soil temperature, soil water and other biotic factors affecting soil respiration should be taken into account.